Recently, a document image filing apparatus has been put in practical use which reads image data, such as documents created in large quantities through two-dimensional scanning by a two-dimensional scanner, stores this read image data on an optical disc, retrieves and reads optional stored image data, and outputs them in a visible state through an output device, for instance, a CRT (Cathode Ray Tube) display device or a printer using an interface.
When it is desirable to combine a reduced image of a document into an image of another document using such an apparatus, image data of one of the documents is read with a scanner and stored in a page memory which is an image memory, and is displayed on a CRT display device. Image data of the other document is read with the scanner, stored in the other region of the image memory, and is displayed on the CRT display device.
A designation is given to reduce the image of the other document at a desired reduction rate, and after executing the reduction process accordingly, the image stored in the region is updated to the reduced size and displayed on the CRT display device. Thereafter, a superimposition with the image of another document is designated. The reduced image stored in the other region is stored in the designated position is the first region according to the designation and then displayed on the CRT display device. Thus, edited images composed of the reduced image of one document superimposed on the image of another document are obtained.
However, such an apparatus has a defect in that the image editing operation is complicated, many image memory areas are needed, and image memory cannot be used efficiently.